In this paper we show that, analogously to how it occurs for black holes, there exist three well-defined laws for Lorentzian wormhole thermodynamics and that these laws are related to a thermal phantomlike radiation process coming from the wormhole throat. It is argued that the existence of wormholes could be manifested by means such as radiation. These results are obtained by analyzing the Hayward formalism of spherically symmetric solutions containing trapping horizons, the phenomenon of phantom accretion onto wormholes, and the development of phantom thermodynamics.

The injection of secondary particles produced by dark matter (DM) annihilation around redshift $\sim 1000$ would inevitably affect the process of recombination, leaving an imprint on cosmic microwave background (CMB) anisotropies and polarization. We show that the most recent CMB measurements provided by the WMAP satellite mission place interesting constraints on DM self-annihilation rates, especially for models that exhibit a large Sommerfeld enhancement of the annihilation cross section, as recently proposed to fit the PAMELA and ATIC results. Furthermore, we argue that upcoming CMB experiments such as Planck, will improve the constraints by at least 1 order of magnitude, thus providing a sensitive probe of the properties of DM particles.

We examine the influence of percent-level dark energy corrections to the nonlinear matter power spectrum on constraints of the dark energy equation of state from future weak lensing probes. We explicitly show that a poor approximation (off by $\gtrsim 10\%$) to the nonlinear corrections causes a $\gtrsim 1\sigma$ bias on the determination of the dark energy equation of state. Future weak lensing surveys must therefore incorporate dark energy modifications to the nonlinear matter power spectrum accurate to the percent-level, to avoid introducing significant bias in their measurements. For the WMAP5 cosmology, the more accurate power spectrum is more sensitive to dark energy properties, resulting in a factor of 2 improvement in dark energy equation of state constraints. We explore the complementary constraints on dark energy from future weak lensing and supernova surveys. A space-based, Joint Dark Energy Mission-like survey measures the equation of state in five independent redshift bins to $\sim 10\%$, while this improves to $\sim 5\%$ for a wide-field ground-based survey like the Large Synoptic Survey Telescope. These constraints are contingent upon our ability to control weak lensing systematic uncertainties to the sub-percent level.

We investigate a mechanism for spontaneous $R$-parity breaking in a class of extensions of the minimal supersymmetric standard model with an extra Abelian gauge symmetry which is a linear combination of $B-L$ and weak hypercharge. Both $U(1{)}_X$ and $R$-parity are broken by the vacuum expectation value of the right-handed sneutrinos, which is proportional to the soft supersymmetric masses. In these models the mechanism for spontaneous $R$-parity violation can be realized even with positive soft masses. In this context one has a realistic mechanism for generating neutrino masses as well as a realistic spectrum. We briefly discuss the possible collider signals which could be used to test the theory, the contributions to proton decay, and the possibility of a gravitino as a dark matter candidate.

We introduce a new class of models describing the quark mass hierarchy. In this class, the dynamics primarily responsible for electroweak symmetry breaking (EWSB) leads to the mass spectrum of quarks with no (or weak) isospin violation. Moreover, the values of these masses are of the order of the observed masses of the down-type quarks. Then, strong (although subcritical) horizontal diagonal interactions for the $t$ quark plus horizontal flavor-changing neutral interactions between different families lead (with no fine-tuning) to a realistic quark mass spectrum. In this scenario, many composite Higgs bosons occur. A concrete model with the dynamical EWSB with the fourth family is described in detail.

White dwarf-neutron star binaries generate detectable gravitational radiation. We construct Newtonian equilibrium models of corotational white dwarf-neutron star (WDNS) binaries in circular orbit and find that these models terminate at the Roche limit. At this point the binary will undergo either stable mass transfer (SMT) and evolve on a secular time scale, or unstable mass transfer (UMT), which results in the tidal disruption of the WD. The path a given binary will follow depends primarily on its mass ratio. We analyze the fate of known WDNS binaries and use population synthesis results to estimate the number of LISA-resolved galactic binaries that will undergo either SMT or UMT. We model the quasistationary SMT epoch by solving a set of simple ordinary differential equations and compute the corresponding gravitational waveforms. Finally, we discuss in general terms the possible fate of binaries that undergo UMT and construct approximate Newtonian equilibrium configurations of merged WDNS remnants. We use these configurations to assess plausible outcomes of our future, fully relativistic simulations of these systems. If sufficient WD debris lands on the NS, the remnant may collapse, whereby the gravitational waves from the inspiral, merger, and collapse phases will sweep from LISA through LIGO frequency bands. If the debris forms a disk about the NS, it may fragment and form planets.

We present a general class of exact solutions in Einstein-Maxwell-dilaton gravity describing configurations of black holes and Kaluza-Klein bubbles magnetized along the compact dimension. Smarr-like relations for the mass and the tension are found. We also derive the mass and tension first laws for the configurations under consideration using the Noether current approach. The novelty is the appearance of new terms in the Smarr-like relations and the first laws containing the magnetic flux. The solutions we consider are also explicit examples showing that in Kaluza-Klein spacetimes the interval (rod) structure and the charges (which are zero by construction for the solutions here), are insufficient to classify the solutions and additional data is necessary, namely, the magnetic flux(es).

We present and analyze exact gyraton and nonexpanding gravitational-wave solutions of algebraic type II on backgrounds which are a direct product of two 2-spaces of constant curvature, or more general type D spacetimes. This family of electrovacuum background spacetimes contains the Nariai, anti-Nariai, and Plebański-Hacyan universes, conformally flat Bertotti-Robinson and Minkowski spaces. The gyraton solutions are given in a simple Kundt metric form. They belong to the recently discussed class of spacetimes with constant scalar invariants of the curvature tensor. We show that the Einstein equations reduce to a set of linear equations on the transverse 2-space which can be explicitly solved using the Green functions.

The growth rate of matter perturbation and the expansion rate of the Universe can be used to distinguish modified gravity and dark energy models in explaining cosmic acceleration. We explore here the inclusion of spatial curvature into the growth factor. We expand previous results using the approximation ${\Omega }_m^{\gamma }$ and then suggest a new form, $f_a={\Omega }_m^{\gamma }+(\gamma -4/7){\Omega }_k$, as an approximation for the growth factor when the curvature ${\Omega }_k$ is not negligible, and where the growth index $\gamma$ is usually model dependent. The expression recovers the standard results for the curved and flat $\Lambda \mathrm{CDM}$ and Dvali-Gabadadze-Porrati models. Using the best fit values of ${\Omega }_{m0}$ and ${\Omega }_{k0}$ to the expansion/distance measurements from Type Ia SNe, baryon acoustic oscillation, WMAP5, and $H(z)$ data, we fit the growth index parameter to current growth factor data and obtain ${\gamma }_{\Lambda }({\Omega }_k\ne 0)={0.65}_{-0.15}^{+0.17}$ and ${\gamma }_{\mathrm{DGP}}({\Omega }_k\ne 0)={0.53}_{-0.12}^{+0.14}$. For the $\Lambda \mathrm{CDM}$ model, the $1-\sigma$ observational bounds are found consistent with theoretical value, unlike the case for the Dvali-Gabadadze-Porrati model. We also find that the current data we used is not enough to put significant constraints when the 3 parameters in $f_a$ are fit simultaneously. Importantly, we find that, in the presence of curvature, the analytical expression proposed for $f_a$ provides a better fit to the growth factor than other forms and should be useful for future high precision missions and studies.

The transverse symmetry transformations associated with the normal symmetry transformations in gauge theories are introduced, which at first are used to reproduce the transverse Ward-Takahashi identities in the Abelian theory QED. Then the transverse symmetry transformations associated with the BRST symmetry and chiral transformations in the non-Abelian theory QCD are used to derive the transverse Slavnov-Taylor identities for the vector and axial-vector quark-gluon vertices, respectively. Based on the set of normal and transverse Slavnov-Taylor identities, an expression of the quark-gluon vertex function is derived, which describes the constraints on the structure of the quark-gluon vertex imposed from the underlying gauge symmetry of QCD alone. Its role in the study of the Dyson-Schwinger equation for the quark propagator in QCD is discussed.

In this article, we investigate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive pion production cross section in proton-proton collisions and present the general formulas for the higher-twist differential cross sections in the case of the running coupling and frozen coupling approaches. The structure of infrared renormalon singularities of the higher-twist subprocess cross section and the resummed expression (the Borel sum) for it are found. We compared the resummed higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. We obtain, that ratio $R=({\Sigma }_{{\pi }^{+}}^{\mathrm{HT}}{)}^{\mathrm{res}}/({\Sigma }_{{\pi }^{+}}^{\mathrm{HT}}{)}^0$, for all values of the transverse momentum $p_T$ of the pion identically equivalent to ratio $r=({\Delta }_{\pi }^{\mathrm{HT}}{)}^{\mathrm{res}}/({\Delta }_{\pi }^{\mathrm{HT}}{)}^0$. It is shown that the resummed result depends on the choice of the meson wave functions used in calculation. Phenomenological effects of the obtained results are discussed.

The transition form factors of ${\overline{B}}_s^0\to D_s^{+}(2317)$ and ${\overline{B}}_s^0\to D_s^{+}(1968)$ at large recoil region are investigated in the light cone sum rules approach, where the heavy quark effective theory is adopted to describe the form factors at small recoil region. With the form factors obtained, we carry out a detailed analysis on both the semileptonic decays ${\overline{B}}_s^0\to D_s^{+}(1968,2317)l{\overline{\nu }}_l$ and nonleptonic decays $B_s\to D_s^{+}(1968,2317)M$ with $M$ being a light meson or a charmed meson under the factorization approach. Our results show that the branching fraction of ${\overline{B}}_s^0\to D_s^{+}(2317)\mu {\overline{\nu }}_{\mu }$ is around $2.3\times {10}^{-3}$, which should be detectable with ease at the Tevatron and CERN LHC. It is also found that the branching fractions of ${\overline{B}}_s^0\to D_s^{+}(1968)l{\overline{\nu }}_l$ are almost 1 order larger than those of the corresponding $B_s^0\to D_s^{+}(2317)l{\overline{\nu }}_l$ decays. The consistency of predictions for $B_s\to D_s^{+}(1968,2317)L$ ($L$ denotes a light meson) in the factorization assumption and $k_T$ factorization also supports the success of color transparency mechanism in the color allowed decay modes. Most two-charmed meson decays of $B_s$ mesons possess quite large branching ratios that are accessible in the experiments. These channels are of great importance to explore the hadronic structure of charmed mesons as well as the nonperturbative dynamics of QCD.

The exclusive two-body nonleptonic $B\to VV$ decays are investigated, within the factorization approximation, in the relativistic independent quark model based on a confining potential in the scalar-vector harmonic form. The branching ratios and the logitudinal polarization fraction ($R_L$) are calculated yielding the model predictions in agreement with experiment. Our predicted $CP$-odd fraction ($R_{\perp }$) for $B\to D^{*}{D}_{(s)}^{*}$ decays are in general agreement with other model predictions and within the existing experimental limit.

In this paper we study the effects of isospin breaking in the dynamical generation of the $X(3872)$ state. We also calculate the ratio of the branching fractions of the $X$ decaying into $J/\psi$ with two and three pions, which has been measured experimentally to be close to unity. Together with the $X(3872)$, of positive $C$ parity, we predict the existence of a negative $C$-parity state, and we comment on which decay channel is more promising to observe this state. The simultaneous investigation of the $X(3872)$ decay into $J/\psi \pi \pi$ and $D^0{\overline{D}}^{*0}$ show a preference for a slightly unbound, virtual state of $D{\overline{D}}^{*}$ and $\overline{D}{D}^{*}$.

We review the Rein-Sehgal model and criticize its use for low energy neutrino induced coherent pion production. We have studied the validity of the main approximations implicit in that model, trying to compare with physical observables when that is possible and with microscopical calculations. Next, we have tried to elaborate a new improved model by removing the more problematic approximations, while keeping the model still reasonably simple. Last, we have discussed the limitations intrinsic to any approach based on the partial conservation of the axial current hypothesis. In particular, we have shown the inability of such models to determine the angular distribution of the outgoing pion with respect to the direction of the incoming neutrino, except for the $q^2=0$ kinematical point.

We generalize modern ideas about the duality between Wilson loops and scattering amplitudes in $\mathcal{N}=4$ super Yang-Mills theory to large $N$ QCD by deriving a general relation between QCD meson scattering amplitudes and Wilson loops. We then investigate properties of the open-string disk amplitude integrated over reparametrizations. When the Wilson-loop is approximated by the area behavior, we find that the QCD scattering amplitude is a convolution of the standard Koba-Nielsen integrand and a kernel. As usual poles originate from the first factor, whereas no (momentum-dependent) poles can arise from the kernel. We show that the kernel becomes a constant when the number of external particles becomes large. The usual Veneziano amplitude then emerges in the kinematical regime, where the Wilson loop can be reliably approximated by the area behavior. In this case, we obtain a direct duality between Wilson loops and scattering amplitudes when spatial variables and momenta are interchanged, in analogy with the $\mathcal{N}=4$ super Yang-Mills theory case.

We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general $p$-brane system. It is found that an effective $p+1$-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the $p+1$-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped ${\mathrm{AdS}}_6\times {\mathrm{S}}^4$ geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at $\tau \to \infty$, while it reduces to a warped static solution at $\tau \to 0$, where $\tau$ is the cosmic time.

Kaluza-Klein (KK) compactifications of higher-dimensional Yang-Mills theories contain a number of 4-dimensional scalars corresponding to the internal components of the gauge field. While at tree level the scalar zero modes are massless, it is well known that quantum corrections make them massive. We compute these radiative corrections at 1 loop in an effective field theory framework, using the background field method and proper Schwinger-time regularization. In order to clarify the proper treatment of the sum over KK modes in the effective field theory approach, we consider the same problem in two different UV completions of Yang-Mills: string theory and lattice field theory. In both cases, when the compactification radius $R$ is much bigger than the scale of the UV completion ($R\gg \sqrt{{\alpha }^{\prime }}$, $a$), we recover a mass renormalization that is independent of the UV scale and agrees with the one derived in the effective field theory approach. These results support the idea that the value of the mass corrections is, in this regime, universal for any UV completion that respects locality and gauge invariance. The string analysis suggests that this property holds also at higher loops. The lattice analysis suggests that the mass of the adjoint scalars appearing in $\mathcal{N}=2$, 4 super Yang-Mills is highly suppressed, even if the lattice regularization breaks all supersymmetries explicitly. This is due to an interplay between the higher-dimensional gauge invariance and the degeneracy of bosonic and fermionic degrees of freedom.

We examine the effects of higher derivative corrections on $\eta /s$, the ratio of shear viscosity to entropy density, in the case of a finite $R$-charge chemical potential. In particular, we work in the framework of five-dimensional $\mathcal{N}=2$ gauged supergravity, and include terms up to four derivatives, representing the supersymmetric completion of the Chern-Simons term $A\wedge \mathrm{Tr}(R\wedge R)$. The addition of the four-derivative terms yields a correction which is a $1/N$ effect, and in general gives rise to a violation of the $\eta /s$ bound. Furthermore, we find that, once the bound is violated, turning on the chemical potential only leads to an even larger violation of the bound.

We explore the nonperturbative renormalization group flow of quantum Einstein gravity (QEG) on an infinite dimensional theory space. We consider “conformally reduced” gravity where only fluctuations of the conformal factor are quantized and employ the local potential approximation for its effective average action. The requirement of “background independence” in quantum gravity entails a partial differential equation governing the scale dependence of the potential for the conformal factor which differs significantly from that of a scalar matter field. In the infinite dimensional space of potential functions we find a Gaussian as well as a non-Gaussian fixed point which provides further evidence for the viability of the asymptotic safety scenario. The analog of the invariant cubic in the curvature which spoils perturbative renormalizability is seen to be unproblematic for the asymptotic safety of the conformally reduced theory. The scaling fields and dimensions of both fixed points are obtained explicitly and possible implications for the predictivity of the theory are discussed. Spacetime manifolds with $R^d$ as well as $S^d$ topology are considered. Solving the flow equation for the potential numerically we obtain examples of renormalization group trajectories inside the ultraviolet critical surface of the non-Gaussian fixed point. The quantum theories based upon some of them show a phase transition from the familiar (low energy) phase of gravity with spontaneously broken diffeomorphism invariance to a new phase of unbroken diffeomorphism invariance; the latter phase is characterized by a vanishing expectation value of the metric.